Metal tear-off cap

ABSTRACT

The invention relates to a metal tear-off cap, the edge of which, separable along a line of reduced strength, securely underlies the rim or ring on the neck or at the mouth of a container, a gripping tab being provided on and projecting beyond the separable edge. The cap is characterized in that the separable edge is rolled-in, in known manner, and is adapted to be pressed in beneath the rim or ring on the neck or at the mouth of the container and in that the line of reduced strength is positioned directly above the rolled-in edge and is interrupted by a cut-away portion which, together with an incision or a previously thinned tear-off zone extending from the line of reduced strength through the rolled-in edge, defines the separable edge, a separate gripping tab, locked on the cap, being secured to the tear-off end.

United States Patent [191 Ritzenhoif 1 Nov. 13, 1973 METAL TEAR-OFF CAPPrimary Examiner-George T. Hall Inventor: Hermann Ritzenhofi,Attorney-Arthur G. Connolly et a1.

Marburg/Lahn, Germany [73] Assignee: Gebruder Seidel KG, 4 [57} ABSTRACTMetallwarenfabrik, Marburg/Lahn, Germany The lnvention relates to ametal tear-off cap, the edge of which, separable along a line of reducedstrength, Flledl J 1972 securely underlies the rim or ring on the neckor at the 21 A 1' N z 258 760 mouth of a container, a'gripping tab beingprovided 1 PP V on and projecting beyond the separable edge. The cap 30F A is characterized in that the separable edge is rolled-in, I J oregnpp [canon llnomy p in known manner, and is adapted to be pressed inbeune 11, 1971 Germany P 21 28 88 6.8 Heath the rim or ring on ma neckor at the mouth of 1 Y the container and in that the line of reducedstrength 2% g is positioned directly above the rolled-in edge and isinterrupted by a cut-away portion which, together 1 d 0 can 15/ 6 39with an incision or a previously thinned tear-off zone extending fromthe line of reduced strength through [56] References cued the rolled-inedge, defines the separable edge, a sepa- UNITED S A S rate grippingtab, locked on the cap, being secured to 3,145,869 8/l964Ritzenlio'ff..,..; 215/46 A the tear-off end. 3,484,012 12/1969 Whiteetal. 215/39 3,363,793 1/1968 Simons 215/46 A 13 Claims, 7 DrawingFigures METAL TEAR-OFF CAP BACKGROUND OF THE INVENTION Various metaltear-off caps are known which are used for sealing bottles and othercontainers and which have an edge which is separable along a line ofreduced strength and which, when the container is opened, is torn off bymeans of a gripping tab projecting beyond this edge. These knowntear-off caps, into the cylindrical surface of which a screw-threadcould be optionally impressed, were primarily intended to be used assafety seals, i.e. as a means for guaranteeing to the first user thatthe original contents of the container sealed by the cap had not beeninterfered with. However, they were less suitable for use as seals whenthe contents of the container were under pressure, since theirresistance to internal pressure was limited. Furthermore, it wasnecessary for the cylindrical portion of the cap, including theseparable edge or tear-off strip, to be of a certain depth, and thiscalled for the use of a corresponding amount of material and also meantthat these caps could only be employed for sealing such containers thathad a suitably long neck with close dimensional tolerances. In addition,the tear-off strips of the knownc aps could not be removed in a reliableand convenient manner.

Metal tear-off caps are also known which have a rolled-in edge. However,these caps have the disadvantage, of being destroyed when torn off,since it was not the rolled-in edge that-was removed but a tear-offstrip extending transversely across the cap.

Also known are tear-off caps in which theline of reduced strength isinterrupted by a cut-away portion which, together with a previouslythinned tear-away zone, defines the tear-off end of the separable edge.However, in the case of these caps too, the separable edge took the formof a wide tear-off strip, so that the depth of the caps was not smalland, for their use,a corresponding length'of neck was required on thecontainers that they were to seal. Furthermore, these caps too offeredonly limited resistance to internal pressure.

SUMMARY OF THE INVENTION The problem underlying the present invention isthat of providing a metal tear-off cap for sealing bottles and othercontainers which, while being of small depth, of-

fers considerable resistance to internal pressure and ensures a veryreliable tear-off action, while at the same time performing the functionof a safety seal.

According to the invention, this problem is solved by means of a cap inwhich the separable edge is rolled-in in known manner and is adapted tobe pressed in beneath the rim or ring on the neck or at the mouth of thecontainer, and in that the line of reduced strength is p0- sitioneddirectly above the rolled-in edge and is interrupted by a cut-awayportionwhich, together with an incision or a previously thinned tear-offzone, extending from the line of reduced strength through the rolled inedge, defines the separable edge with a separate gripping tab, locked onthe cap, being secured to the tearoff end.

Since, in the case of the tear-off cap of the present invention, thebent-over and separable lower edge is rolled-in, its strength isgreatlyincreased as a result of the work-hardening and it ensuresconsiderable resistance to internal pressure on the part of the cap.Since, on the otherhand, this rolled-in edge is only of small depth, theoverall depth of material used for the cap is reduced, so that the capcan also be used for such bottles and other containers that have only anarrow rim with a portion of reduced diameter. Such containers areparticularly easy to produce, since the parts of the mouth in whichclose dimensional tolerances are required are located directly below thesealing rim at the opening. It is at this point that, for example, theglass of the container can be most readily shaped to close dimensionaltolerances. With the tear-off cap of the invention, it is evenpossible-to seal containers that are of THE DRAWINGS FIG. 1 is a sideview of a tear-off cap'in accordance with the invention;

FIGS. 2A and 2B are side views of tear-off caps with the lower edgepartially torn off;

FIG. 3 is a section on the line 3-3 through the tear-off cap of FIG. 1;

FIG. 4 is a corresponding section through a tear-off cap of anotherform;

FIG. 5 is a side view of a further form of tear-off cap, the grippingtab having been omitted from the drawing; and

FIG. 6 is a section through a special container neck sealed by atear-off cap in accordance with the invention.

DETAILED DESCRIPTION Each tear-off cap has a separable edge 1 which isrolled-in by known methods and which also acts as a tear-off strip and asafety strip. By means of this edge 1, which may be turned overoutwardly or inwardly and does not require to be fully rolled-in, thecap is secured to the neck of the container when edge 1 is closed up,and the container is sealed in such a way that any initial unauthorizedopening of the container can be detected. A line 2 of reduced strengthis positioned directly above the rolled-in edge 1. The expressiondirectly above is here also intended to include the location of the line2 at a distance of about 1 to 1.5 mm away from the edge 1. Above theedge I and the line 2 of reduced strength that helps define it, ascrew-thread, not shown, can be provided in known manner in thecylindrical surface of the cap, this screw-thread being used for re- 1sealing purposes.

The line 2 of reduced strength, which is positioned above the rolled-inedge 1 and along which the edge can be torn off, is interrupted by thecut-away portion 3. This cut-away portion 3, which may be constitutedfor example by a punched-out rectangle or a perforationv formed by meansof a mandreLcombines with the tear-off zone 4 to define the tear-off end6 of the separable edge 1, and serves to secure the separate grippingtab 5 locked'on the cap.

The tear-off zone 4 is constituted by an incision or a previouslythinned line which extends from the line 2 of reduced strength throughthe separable edge 1. This tear-off zone 4 is preferably offsetlaterally from the cut-away portion 3, as shown in FIG. 1. However, itmay also be immediately contiguous with the cut-away portion 3 as shownin FIG. 5.

The gripping tab 5 may be made of plastic material, fabric or metal, andparticularly of a light metal such as aluminum. A colored material isparticularly advantageous so that the gripping tab can be readily seen.

In a preferred embodiment of the invention, the gripping tab 5 is madefrom a strip which is coated with an adhesive on one side and whichadvantageously consists of a plastic tape having a thickened edge.Referring to FIG. 3 an adhesive strip of this kind is inserted by one ofits ends through the cut-away portion 3. The longer end of the adhesivestrip passes round the rolledin edge 1, is then bonded over a shortlength 9 to the shorter end of the strip and is stuck to the cap over afurther short length 10. The outer end 11 of the adhesive strip isfolded over and bonded to form a free tab which can be easily gripped atany time. However, the parts and 11, particularly in the case of shallowcaps, may also be laid on the top face 12 of the cap. In sucharrangement, recess can be formed in the top face 12 so that the freeend 11 does not project.

To prevent the gripping tab 5 from sliding off the end 6 of the edge 1when the latter is torn off, the tear-off end 6 as shown in FIG. 2A, ispreferably provided with a nose 7 at a point in front of the grippingtab 5, which nose can be stamped cut at the same time as the cutawayportion 3. Referring to FIG. 2B the same object can also be achieved ifthe tear-off end 6 has an outwardly or upwardly extending retaining pip8 close to the gripping tab 5. This retaining pip may also be lo-' catedat the center of a gripping tab made of adhesive strip, particularlywhen a reinforcing filament extends through the middle of the adhesivestrip, which filament is secured in the retaining pip.

In a further embodiment of the invention, the gripping tab 5 is made ofa plastic film or metal foil which is looped and welded or riveted up inthe cut-away portion 3. FIG. 4 shows an arrangement of this kind inwhich the gripping tab 5 is made of metal, preferably a light metal, andis secured in a recess 13 in the top face 12. The gripping tab can besecured in any known manner, for example by the outer end 11 beingshaped to form an eye which is held by a stud-like device in the recess13 on the top face 12. In this arrangement, the gripping tab 5 is foldedover and riveted up at the point 14 in the cut-away portion 3.

After the container has been sealed, the line 2 of reduced strengthpreferably lies below the rim or ring on the neck or at the mouth of thecontainer. Thus, after the lower edge 1 has been torn off, the cap canbe used again as a removable push-on seal to prevent dust frompenetrating into the container. This is very desirable when, forexample, the container is used for accommodating baby food. The slightlyinwardly curved edge of the reusable push-on cap remaining after thestrip 1 has been torn off then snaps into the complementary portion ofreduced diameter below the rim or ring on the neck or at the mouth ofthe container, when the latter is closed again.

FIG. 6 shows that apart from it being possible to use the tear-off capof the invention for sealing normal containers having at least a rim atthe neck and optionally a screw-thread in addition, the cap can also beemployed for sealing containers having necks of uniform wall-thicknessand mouths which are simply bent outwards at right angles at the top.

As used in the claims the term flange is intended to refer to either thering or rim on the discharge end (i.e. neck or mouth) of the container.

What is claimed is:

1. In a metal tear-off cap having an edge which is separable along aline of reduced strength for securely underlying the flange at thedischarge end of the container, the cap having a gripping tab providedon and projecting beyond the separable edge, the improvement being saidseparable edge is of rolled-in construction for being pressed in beneaththe container flange, said line of reduced strength being positioneddirectly above said rolled-in edge, a tear-off end being provided onsaid separable edge, said tear-off end being defined by a cut-awayportion at said line of reduced strength above said tear-off end andconnected to a tear-off zone along said tear-off edge through saidrolled-in edge, and a separate gripping tab locked on said cap andsecured to said tear-off end.

2. A tear-off cap according to claim 1, characterized in that saidtear-off end has a nose at a point in front of said gripping tab.

3. A tear-off cap according to claim 1, characterized in that saidtear-off end has an outwardly extending retaining pip close to thegripping tab.

4. A tear-off cap according to claim 1, characterized in that saidtear-off zone extending from said line of reduced strength through saidrolled-in edge is offset laterally from said cut-away portion.

5. A tear-off cap according to claim 1, characterized in that saidgripping tab is made of a strip coated with adhesive one one side.

- 6. A tear-off cap according to claim 5, characterized in that theadhesive strip is made from a plastic tape having a thickened edge.

7. A tear-off cap according to claim 5 characterized in that saidadhesive strip passes through said cut-away portion and around saidrolled-in edge and above said rolled-in edge, said strip having twoadhesive faces which are first joined together over a short distance, anadhesive face then being bonded to said cap over a short distance, andthe end of said strip then being folded and its faces stuck together.

8. A tear-off cap according to claim 7, characterized in that theportion of the adhesive strip connected to said cap is located on thetop face of said cap.

9. A tear-off cap according to claim 1, characterized in that thegripping tab is made of a film which is folded over and secured in thecut-away portion.

10. A tear-off cap according to claim 1, characterized in that saidgripping tab is made of metal and is secured in a recess in the top faceof said cap.

11. A tear-off cap according to claim 1, characterized in that the lineof reduced strength is located beneath the flange after the dischargeend of the container has been sealed.

12. A tear-off cap according to claim 1, characterized in that saidtear-off zone being severed from said edge.

13. A tear-off cap according to claim 1, character ized in that saidtear-off zone being a thinned section connected to said edge.

1. In a metal tear-off cap having an edge which is separable along aline of reduced strength for securely underlying the flange at thedischarge end of the container, the cap having a gripping tab providedon and projecting beyond the separable edge, the improvement being saidseparable edge is of rolled-in constructioN for being pressed in beneaththe container flange, said line of reduced strength being positioneddirectly above said rolled-in edge, a tear-off end being provided onsaid separable edge, said tear-off end being defined by a cut-awayportion at said line of reduced strength above said tear-off end andconnected to a tear-off zone along said tear-off edge through saidrolled-in edge, and a separate gripping tab locked on said cap andsecured to said tear-off end.
 2. A tear-off cap according to claim 1,characterized in that said tear-off end has a nose at a point in frontof said gripping tab.
 3. A tear-off cap according to claim 1,characterized in that said tear-off end has an outwardly extendingretaining pip close to the gripping tab.
 4. A tear-off cap according toclaim 1, characterized in that said tear-off zone extending from saidline of reduced strength through said rolled-in edge is offset laterallyfrom said cut-away portion.
 5. A tear-off cap according to claim 1,characterized in that said gripping tab is made of a strip coated withadhesive one one side.
 6. A tear-off cap according to claim 5,characterized in that the adhesive strip is made from a plastic tapehaving a thickened edge.
 7. A tear-off cap according to claim 5characterized in that said adhesive strip passes through said cut-awayportion and around said rolled-in edge and above said rolled-in edge,said strip having two adhesive faces which are first joined togetherover a short distance, an adhesive face then being bonded to said capover a short distance, and the end of said strip then being folded andits faces stuck together.
 8. A tear-off cap according to claim 7,characterized in that the portion of the adhesive strip connected tosaid cap is located on the top face of said cap.
 9. A tear-off capaccording to claim 1, characterized in that the gripping tab is made ofa film which is folded over and secured in the cut-away portion.
 10. Atear-off cap according to claim 1, characterized in that said grippingtab is made of metal and is secured in a recess in the top face of saidcap.
 11. A tear-off cap according to claim 1, characterized in that theline of reduced strength is located beneath the flange after thedischarge end of the container has been sealed.
 12. A tear-off capaccording to claim 1, characterized in that said tear-off zone beingsevered from said edge.
 13. A tear-off cap according to claim 1,characterized in that said tear-off zone being a thinned sectionconnected to said edge.